Mastadooms are large skeletal mammoths encountered on Star Hill in Super Mario RPG: Legend of the Seven Stars. Mastadooms are possibly the most powerful enemy on Star Hill, having an arsenal of physical attacks and the powerful "Drain Beam" attack, which hurts all party members. A Mastadoom's regular attack consists of hitting its opponents with its long trunk. Mastadooms are strong against Thunder, but their main weakness is Fire.

An unused enemy, the Mastablasta.

Only one Mastadoom ever appears in battle. There is also an unused enemy named Mastablasta, a blue-colored version of Mastadoom. They could actually summon Goombas to help them in battle, and had the psychopath, "Life is tough, ain't it?"

It is worth noting that Mastadoom is anatomically incorrect, as real-life elephants (and by extension, mastodons and mammoths) lack bones in their trunks.